Abstract: A cylindrical portion of the tool or workpiece is rotatably supported by two pairs of spherical rollers rotatably carried by two pairs of holders mounted on first and second upright supports secured to a bed. The second support is adjustable to change the spacing between the supports. The holders have screw threads for adjusting the spacing between the rollers. Alternatively, separate feed screws are provided for the holders. A drive belt is looped around the workpiece and around a drive pulley rotatably mounted on a movable carriage biased by a spring to tighten the belt. A knob is provided to rotate the drive pulley. The flights of the belt are pinched toward each other by a pair of guide pulleys and by a pair of rollers adjacent the drive pulley, whereby the upper loop of the belt is kept open and close to the location of the workpiece when it is removed. The carriage may be latched in a belt-loosening position by a swingable latching arm.